Alkyd resins have long been used as ingredients in coating compositions that are applied to various materials. For example, cured films resulting from aqueous alkyd coating compositions may be used as protective paint coatings for farm implements. The coating compositions generally comprise an alkyd resin that is dissolved or dispersed in an aqueous medium. Such compositions may include inert fillers, pigments, anticorrosive agents, drying agents, and the like.
Alkyd resins generally are formed by the polymerization of polyols and polybasic acids in an esterification reaction; included in the reaction mixture may be monobasic acids, fatty acids and the like. The aqueous coating compositions formed from such alkyd resins often may exhibit poor hydrolytic stability; that is, the aqueous resin compositions often do not have the capacity to withstand storage at high summertime storage temperatures normally found in warehouse and manufacturing facilities for long periods of time. Hydrolysis of the alkyd may result in separation of the coating composition into phases, accompanied often by settling of solid materials to the bottom or substantial reductions in viscosity and diminished performance of the coating material.